To Notes

IT 130 -- 11/4/08

Review Questions

1. What is the output?

   var a = 5, b = 8, c;
   c = b + 3 * a;
   b = 2 * b + c;
   a = 3 * b;
   document.write("<p> + (a + c) + </p>");
   

   Answer: Variable Trace
   

   a	b	c
   5	8	23
   117	39

   Output: 140

2. Write code for a dropdown menu that displays the items "Beef", "Chicken", "Vegetarian". The corresponding values are "1", "2" and "3". The name of the dropdown menu should be ddmMealChoice.

   Ans:
   

   <select name="ddmMenu">
   <option value="1">Beef</option>
   <option value="2">Chicken</option>
   <option value="3">Vegetarian</option>
   </select>
   

3. Write a JavaScript statement that assigns the currently displayed item in ddmMealChoice in the textbox txtMealChoice.

   Ans:
   

   document.frmMenu.txtMealChoice.value = 
       document.frmMenu.ddmMenu.value
   

Structured Programming

• Structured Programming Background

• Structured Programming in Everyday Life

• Structured Programming in JavaScript

Using Decision (If Statements)

• Examples:
  CoinFlip   TemperatureDescriptors   Overtime

  TrueFalseQuiz   ConsultantBSGenerator   VotingMachine

• Variable Traces:
  Decision1   Decision2   Decision3

Practice Problem

• Write a JavaScript function that gets a grade from an input textbox. It enters "Pass" in the output textbox if the grade is >= 60 and "Fail" otherwise.

Using Repetition (While Loops)

• Examples:
  100-bottles-of-beer.htm   fair-coin-test.htm

  fair-die-test.htm   snake-eyes.htm

Radio Buttons

• Look at the Radio Button Example